JP2008534408A - Dual mode operation type electric roll tube system - Google Patents

Abstract

A motorized system for reeling and unreeling a flexible member on a roller tube between fully open wound and fully closed unwound conditions to minimize sound pressure level has a rotatable roller tube and a flexible member that winds on the tube. A d-c motor drives the tube through a gear reduction. The motor has a motor speed versus torque characteristic extending linearly from high maximum RPM, low minimum torque, to low minimum RPM high maximum torque with peak efficiency at a given RPM. The motor moves the member between the two positions at a motor speed less than the given peak efficiency RPM and less than 50% of high maximum RPM with efficiency less than 25% of peak efficiency, intentionally at a high torque and low efficiency. The motor has two or more modes each moving the member at predetermined different linear speed.

Description

The present invention is a related application of US patent application Ser. No. 11 / 096,783 filed Apr. 1, 2005 and claims priority.
The present invention relates to an electric roll tube system used to wrap flexible members such as shades, screens and the like, and more particularly to a drive assembly for an electric roll tube system.

  Referring to FIG. 1, a motorized roll tube system 10 having a conventional drive assembly 12 is shown. The system 10 includes a roll tube 14 that is rotatably supported and a flexible member 16 such as a window shade fabric wound around the roll tube 14. The end of the flexible member 16 is typically fixed to the roller tube 14 and engaged with the roll tube 14. Various methods for fixing the flexible member 16 to the roll tube 14 are known. For example, a double-sided tape is used, or a lock provided with a clip member outside the roll tube 14 is used. For example, stopping over the flexible member 16 in the groove is included. The roll tube 14 is driven in opposite directions by the drive assembly 12 to wrap and unwind the flexible member 16 relative to the roll tube 14. The conventional drive assembly 12 includes an elongate housing 18 and a pack 20 positioned adjacent to the end of the housing 18, the pack 20 engaging the inner surface of the roll tube 14, and the drive assembly 12 is connected to the pack 20. Is rotated, the roll tube 14 is driven.

  The conventional roll tube drive assembly 12 includes a motor 22 and a gear assembly 24 positioned within the housing 18 and coupled to the pack 20. The motor 22 and the gear assembly 24 are shown in FIG. 2 with the housing 18 omitted. The motor 22 of the conventional drive assembly 12 is a DC motor. Referring again to FIG. 1, the assembly 12 is received inside the roll tube 14, so this type of roll tube drive assembly is referred to as a "built-in" drive assembly. Other known motorized roll tube systems include a drive assembly positioned outside the roll tube.

  The motor 22 includes an output shaft 23 that is rotated by the motor at a rotational speed referred to herein as “motor speed”. In the conventional drive assembly 12, the motor is operated at a motor speed of about 2000 rpm. A gear assembly 24 coupled to the output shaft of the motor 22 reduces this relatively high 2000 rpm input motor speed to a relatively slow output rotational speed of about 27 rpm for the roll tube 14. Thus, in the gear assembly 24 of the conventional drive assembly 12, the gear ratio is approximately 74: 1 (i.e., 2000/27).

  Since the torque capacity of the motor varies depending on the motor speed, the motor of the electric roll tube system needs to provide sufficient torque capacity at the operating motor speed to wrap the flexible member 16 on the roll tube 14. Referring to FIG. 3, the performance characteristics of the motor 22 with a conventional drive assembly 12 are graphically displayed. This type of graph is referred to as a “motor curve”. The relationship between the motor speed (shown on the Y axis) and the torque capacity of the motor (shown on the X axis) is shown by line 26. As shown, the maximum motor speed of the motor 22 is about 3150 rpm and the maximum motor torque capacity is about 280 m-Nm. As also illustrated, the torque capacity of the DC motor 22 varies linearly over the entire motor speed range. In other words, the torque capacity of the motor increases with decreasing motor speed, even when the motor speed decreases as it approaches zero. In FIG. 3, the torque value of the motor along line 26 representing speed versus torque represents the torque capacity rather than the torque of the motor in operation. In other words, the motor 22 may be operated at a given motor speed with any torque between 0 (ie, no load condition) and a value along the line 26 representing speed versus torque. The torque capacity of the motor 22 when the operation speed is 2000 rpm is about 99 m-Nm.

  As shown by the efficiency curve 28 in FIG. 3, the efficiency of the motor 22 varies depending on the motor speed. The motor efficiency shown along with the motor speed on the Y-axis is determined by reading the value of the position obtained by drawing a vertical line from the line 26 representing speed versus torque to the efficiency curve 28. Therefore, the efficiency of the motor 22 of the conventional drive assembly 12 when the motor operating speed is 2000 rpm is about 25%. As shown, a motor efficiency of 25% is the peak efficiency of the motor 22. Motor speed related to peak efficiency is referred to herein as peak efficiency motor speed. The peak efficiency motor speed is about 65% of the maximum motor speed (ie 2000/3100).

  Specific motor speed, torque capacity, and motor efficiency vary with different DC motors, but certain characteristics are common to all DC motors. First, motor speed and motor torque capacity vary linearly and inversely throughout the entire range of motor speed, including very low speeds approaching zero. Also, the motor efficiency generally reaches peak A efficiency under light load conditions (that is, when the motor speed is 50% or more of the maximum motor speed and the torque capacity is relatively small). The motor of a conventional drive assembly is driven by the drive assembly near the peak efficiency of the motor speed under light load conditions. Motor manufacturers recommend motor operation under such relatively light load conditions as described in detail below.

A known roll tube drive assembly gear assembly includes a planetary spur gear. It is desirable that the planetary spur gear is structurally economical and more efficient in terms of power transmission than other types of gears. However, in the spur gear, the surrounding teeth mesh with each other during operation. The noise at the time is loud compared to other types of gears. These contact sounds associated with gear meshing are often referred to as “gear strikes” and increase with increasing rotational speed of the gears that mesh. Known gear assemblies also include gear stages with helical gears. The helical gear includes an elongated helical flight portion that always engages the flight portion of another helical gear. However, helical gears are both less economical and more efficient than spur gears.
The gear assembly 24 of the conventional drive assembly 12 is a hybrid gear system that includes three gear stages 30, 32, 34, where the first stage 30 has a helical gear and each of the second and third stages 32, Reference numerals 34 each have a planetary spur gear. Since the first gear stage 30 is positioned closest to the motor 22, each gear of the first gear stage 30 rotates at a relatively high speed of 2000 rpm. However, the rotational speeds of the second and third gear stages 32, 34 are stepped down from a motor speed of 2000 rpm.
Conventional electric roll tube systems include a system for variable speed control of a drive assembly motor. The functional structure of the variable speed control is to make the movement of the flexible member substantially constant (known as “linear velocity” or “fiber velocity”), and the flexible member is wound on the roll tube. As the winding layer is formed, the roll tube rotational speed is adjusted by the variable motor speed as the effective winding radius changes accordingly. If the rotational speed of the roll tube is constant, the fiber speed will change as the effective winding radius changes. In the conventional electric roll tube system, as the flexible member is wound around the roll tube, the motor speed is reduced to make the fiber speed substantially constant.

US patent application Ser. No. 10 / 774,919 US Pat. No. 5,848,634

  However, the conventional electric roll tube system does not provide multi-mode operation in which the fiber speed in each mode is different.

  According to the present invention, an electric roll tube system is provided that includes a roll tube that is rotatably supported and a flexible member that is engaged with and received by the roll tube. The electric roll tube system further includes an output shaft rotating at a motor speed and a gear assembly coupled to the output shaft and driven by the motor. The gear assembly includes a plurality of gear stages adapted to produce an output rotational speed that is reduced with respect to motor speed.

The electric roll tube system further includes a controller coupled to the motor for controlling the motor to cause the flexible member to be wound or unwound with respect to the roll tube. The controller of the present invention is adapted to provide at least two modes of operation for moving the flexible member at different linear speeds.
In one embodiment of the present invention, the operation modes include a setup mode and an ultra-low speed mode. The linear speed in the setup mode is larger than that in the ultra-low speed mode. In one currently preferred embodiment of the present invention, the linear speed in the setup mode is at least twice that of the ultra-low speed mode.

In one embodiment, the electric roll tube system has a noise level of about 3 dBA when operating in ultra-low speed mode, or much less than that when operating in setup mode.
In one embodiment, the controller is responsive to the input light level to adjust the position of the flexible member in response to the input light level to the controller.

  Referring to the drawings in which like reference numbers represent like elements, FIGS. 4-6 show a roll tube drive assembly 40 in accordance with the present invention, which includes a motor 42, a gear assembly 44, and an elongated housing 41. Is included. The drive assembly 40 is received in a roll tube such as the roll tube 14 shown in FIG. 1 and engages the inner surface of the roll tube to rotate the roll tube and wind or unwind a flexible member such as a window shade. It is like that. The configuration in which the drive assembly 40 is received within the roll tube and engages the inner surface of the roll tube is similar to that described with respect to the conventional drive assembly 12. However, as will be described in detail below, the drive assembly 40 of the present invention reduces the roll tube diameter for driving a predetermined load, or in other words, a novel drive for driving a roll tube of a predetermined diameter with a large load. Shaped in style. In this new configuration, the operation sound generated by the roll tube is relatively quiet, while a spur gear transmission mechanism is desirably used throughout the gear assembly 44.

  The motor 42 of the drive assembly 40 is preferably a DC motor. The motor 42 has an output shaft 43 that transmits mechanical power under motor speed and motor torque. DC motors are reliable, relatively inexpensive, and have adequate torque capacity even in small enough sizes for most roll tube applications. There are brush types and brushless types of DC motors, and their torque / speed curves are similar. However, in the brushless type, contrary to the brush type, the wound stator is arranged to surround the permanent magnet rotor. The brushless type motor does not require a motor brush that allows the brush type motor to flow current to the winding rotor. The stator windings of the brushless motor are electronically rectified and require control electronics to control the current flow. A variety of brushed DC motors are currently available and are therefore preferred for economic reasons.

  Most of the drive assembly 40 noise generated by the motor 42 is in the gear assembly 44. These noise generating elements are shown in FIG. 5, which omits other parts of the drive assembly 40 to facilitate comparison with the corresponding elements of the conventional drive assembly 12 of FIG. It is shown as it was. The gear assembly 44 of the drive assembly 40 includes first and second gear stages 46, 48 for reducing the rotational speed of the motor 42 to a desired rotational speed for rotating the roll tube that receives the drive assembly 40. . Each gear of the first and second gear stages 46 and 48 is a planetary spur gear. As described above, the planetary spur gear is used through all the gear stages of the gear assembly 44 because the spur gear is economical and the first gear stage uses another type of gear such as a helical gear. This is desirable because the transmission efficiency of the gear is increased as compared with that of the drive assembly 12. The planetary spur gear of the gear assembly 44 is preferably made of plastic.

  Referring to FIG. 7, the motor curve of the motor 42 is shown. Similar to that of FIG. 3, which is the motor curve of the motor 22, FIG. 7 graphically represents various performance characteristics of the motor 42 including motor speed, motor torque capacity, and motor efficiency. As shown by line 51, the motor speed and motor torque capacity of motor 42 varies linearly and inversely throughout the entire range of motor speed, including very low speeds approaching zero, similar to that of motor 22. To do. The motor 42 has a maximum motor speed of about 4200 rpm and a maximum motor torque capacity of about 122 m-Nm. As shown by the efficiency curve 53, the motor efficiency of the motor 42 reaches a peak value of about 75% when the motor is operated at a speed of about 3700 rpm.

  The motor curve shown in FIG. 7 includes a recommended operating range by the motor manufacturer, shown as shaded area 55. As shown, this recommended operating range for the motor 42 includes motor speeds corresponding to relatively high load conditions (ie, relatively high speed and relatively low motor torque). The manufacturer's recommended operating range includes peak efficiency at a motor speed of 3700 rpm, which is not surprising. As discussed above, in conventional roll tube drive assemblies, the motor is operated at light load conditions according to the manufacturer's recommendations. Specifically, the manufacturer recommends operating the motor 42 at a motor speed of about 3200 rpm or higher, that is, operating between about 76-100% of the maximum motor speed of the motor 42, 4200 rpm. The recommended operating range of the motor 42 includes the peak efficiency at a motor speed of 3700 rpm, as in the motor 18.

It seems intuitively preferable to operate the motor of the roll tube drive assembly within the recommended operating range of the manufacturer according to the practice of the world. As discussed above, the recommended operating range includes peak efficiency motor speed, so that the motor operates efficiently in the recommended operating range, and the load conditions associated with this recommended range are relatively light (i.e. (Relatively low torque), which limits the damage caused by overheating when the motor is operated under heavy load, thus extending the motor life.
However, the drive assembly 40 does not have the form of operating the motor 42 within the manufacturer's recommended operating range in a conventional manner, and with a preferred motor speed range represented by the shaded area 57 in FIG. High torque) is preferable. A preferred operating range, the shaded area 57, includes a motor speed of 0 to about 1500 rpm as shown. The upper limit speed of 1500 rpm is approximately 36% of the maximum motor speed of the motor 42, 4200 rpm. In the drive assembly 40, it is most preferred to operate the motor 42 at a speed of about 850 rpm, which is only about 20% of the maximum motor speed. As shown by the line 51 in FIG. 7, when the motor 42 is operated at a speed of 850 rpm, the torque capacity of the motor 42 is 98 m−Nm, and the motor efficiency is about 19% as shown by the curve 53. This motor efficiency is only about 1/4 (ie 19/75) of the peak efficiency of the motor 42. The drive assembly 40 of the present invention is configured to operate the motor 42 at a motor speed that is far outside the recommended operating range and is very inefficient for the motor.

  The torque capacity of 98 m-Nm of the motor 42 when operating at 850 rpm is approximately equal to the torque capacity of 99 m-Nm obtained when the motor 22 of the conventional drive assembly 12 is operated at a speed of 2000 rpm. The motor 22 is about 4.1 cm (1.65 in) in diameter, while the motor 42 is only about 3.1 cm (1.22 in) in diameter. Thus, the present invention may provide a similar torque capacity for driving a similar application load by operating the motor inefficiently at speeds outside the recommended operating range, while reducing the diameter of the motor. It is. As the motor diameter is reduced, the required diameter of the roll tube is reduced considerably. Reduction of the roll tube diameter is aesthetically desirable in order not to make the installation appearance bulky. The present invention can also be used to increase the motor driven load by increasing the torque capacity instead of decreasing the motor diameter.

The conventional drive assembly 12 is about 6.8 cm (2.7 in) long, and the motor 22 has an aspect ratio (ie, length to diameter) of about 1.64 (ie, 2.7 / 1.65). is there. This aspect ratio is typical for standard torque motors. The motor 42 of the drive assembly 40 of the present invention is also about 6.8 cm (2.7 in) long, but the motor 42 has an aspect ratio of about 2.21 (ie, 2.7 / 1.22). The effect of increasing the aspect ratio in the motor 42 is shown in FIGS. It is known that the torque capacity of a motor varies in proportion to BID ² L where B is the magnetic flux, I is the current, and D and L are the motor diameter and length, respectively, thus the motor torque capacity is Increasing any one of B, I, D, and L increases. The motor 42 is considered to be a “high” torque motor because the aspect ratio of the motor 42 is larger than that associated with a standard torque motor. The increase in torque capacity obtained by increasing the aspect ratio (ie, increasing the length) partially offsets the decrease in torque capacity associated with the smaller diameter of the motor 42. Since the diameter D is squared in the previous relationship (ie BID ² L), the effect of diameter reduction on torque capacity is much greater than the same effect due to increased length.
Therefore, according to the present invention, the torque capacity is increased even when the small-diameter motor is operated under the heavy load condition related to the hatched shaded region 57, which is the preferred operating range described above.

As previously mentioned, the torque capacity value 98m-Nm provided by the motor 42 operating at a motor speed of 850 rpm is 99m which is the torque capacity value obtained when the conventional drive assembly 12 is operated at a motor speed of 2000 rpm. Although approximately equal to -Nm, the present invention is not limited to any particular torque capacity. Thus, the drive system can be configured to include a much smaller diameter motor with a reduced torque capacity compared to the motor 42 for use in a smaller diameter roll tube. For example, a motor having a maximum torque capacity value between 50 m-Nm and 75 m-Nm can be used to drive a roll tube having a diameter of about 4.1 cm (1.625 in).
As discussed above, the planetary spur gear is preferred as a gear type in terms of its economic efficiency and gear effect, but is expected to be driven at a relatively high motor speed associated with conventional drive assemblies. It's too noisy. However, in the present invention, by reducing the motor speed to about 850 rpm, it is possible to desirably use such spur gears in each stage of the gear assembly 44 without excessive noise caused by gear striking in the first gear stage 46. it can. As described above, when the motor speed is reduced to 850 rpm, the required gear ratio of the gear assembly 44 is also reduced to about 20: 1. As a result, the number of gear stages can be reduced from 3 to 2. When the number of gear stages is reduced, the total number of gears in the gear assembly is reduced, and noise generated from the gear assembly is further reduced.

  The drive assembly of the electric roll tube system is preferably capable of variably controlling the motor speed of the drive assembly motor. Such variable speed control is desirable in order to substantially constant the movement of the flexible member wound on the roll tube, considering that the effective wrap radius changes. The flexible member forms a layer (or “wrapped”) as it is wound into a roll tube, and the effective wrapping radius changes as the flexible member is wound or unwound. Thus, when the roll tube is driven at a constant rotational speed, the moving speed of the flexible member (often "linear speed" or "fiber speed") varies as the effective winding radius changes. In order to keep the fiber speed constant, it is necessary to decrease the rotational speed as the flexible member is wound on the roll tube. Thus, the rotational speed is maximized at or near the time when the flexible member is completely unwound from the roll tube (ie, in the “fully lowered” or “fully closed” position). When the flexible member is at the fully lowered position, the amount of winding of the flexible material around the roll tube is minimum, and the volume attenuation of the roll tube by the flexible material is minimum. Thus, the sound pressure level produced by the electric roll tube system is maximized when the drive assembly drives the roll tube when the flexible material is at or near the fully lowered position.

  According to the present invention, there is provided a drive assembly 40 that desirably includes a spur gear in each gear stage of the gear assembly 44 while suppressing noise generated by the drive assembly. The electric roll tube system includes a drive assembly 40 housed in a roll tube having a diameter of about 4.1 cm (1.625 in), which is about 0.91 Nm (about 8.1 in-lb :). 10 pounds of flexible member added to a radius of 0.81 inch). The volume level generated by the electric roll tube system was measured using a sound pressure meter at a position about 1 m (3 ft) away from the drive end of the roll tube. The sound pressure level generated when the drive assembly 40 drives the roll tube when the flexible member is at or near the fully lowered position (ie, the maximum volume level resulting from the electric shade assembly) is the ambient sound pressure level. Was about 43 dBA in an environment where the value was 38 dBA. The ambient sound volume level of 38 dBA is a sound pressure level in a relatively quiet office environment such as a private office with a door closed. If the sound pressure level generated by the electric roll tube system with the above setting is about 40 to 44 dBA, it is considered that the sound pressure level is not disturbed and comfortable. The sound pressure level generated by the drive assembly of the present invention, which drives the spur gear at a much lower rotational speed than that associated with the motor manufacturer's recommended operating range, allows the spur gear to operate at a higher rotational speed than such recommended operating range. It was preferable compared to that of a conventional electric roll tube system to be driven. The conventional electric roll tube system includes a system in which the sound pressure level exceeds 50 dBA at a position about 1 m (3 ft) away from the drive end of the roll tube in an environment where the ambient sound pressure level is 38 dBA. In such an ambient sound pressure environment, a sound pressure exceeding 50 dBA is considered to be bothersome and uncomfortable.

The gear assembly 44 described above includes two gear stages 46, 48, but the number of gear stages is not critical. Thus, a drive assembly according to the present invention may include more than two gear stages as shown in the embodiments described above. However, as discussed above, when the number of gear stages is reduced, the total number of gears in the gear assembly is reduced and the gear hitting noise is also reduced.
As discussed, it is counterintuitive that the operating efficiency of the motor 42 by the drive assembly 40 deteriorates under heavy load conditions. In addition to poor motor operating efficiency, maintaining the motor operating under heavy load torque conditions associated with the preferred operating range, the shaded area 57, will cause the motor to overheat and possibly reduce its lifetime. Take damage. However, the motor of the electric roll tube system is not normally operated continuously. Typical electric roll tube systems, such as shade fibers in window shades, are rolled up in the morning, unwound at night, and adjusted several times during the day . Thus, except in most special situations, the motor 42 will not be clearly affected by inefficient operation by its lifetime. However, to protect the motor 42, the drive assembly 40 can be configured to track the actual working time of the motor 42. In this case, the motor 42 is stopped when an excessive operation occurs that would have adversely affected the motor if the motor is operated as it is during the predetermined period. Alternatively, the condition of the motor can be monitored based on the temperature of the motor or related components, or using a thermocouple, thermistor, temperature sensor or other suitable detection device.

  With reference to FIG. 4, the structural details of the drive assembly 40 will be further described. The elongated housing 41 has a tubular shape and defines an inner portion that houses the drive motor 42 and the gear assembly 44. The drive assembly 40 preferably includes an electronic unit (“EDU controller”) 50 for controlling the operation of the drive motor 42. The EDU controller 50 includes a printed circuit board 52 for mounting its control circuit (not shown) and may have a configuration for tracking the run time of the motor 42 in the manner described above, with the motor 42 being excessive in a given engine. Stop the motor if it is used and the motor is likely to be damaged. The EDU controller 50 includes a bearing sleeve 54 and a bearing mandrel 56 adjacent to the end of the housing 41. Electronic drive units for electric roll tube systems are known and will not be described here.

  The drive assembly 40 includes a drive pack 58 positioned adjacent to the end of the housing opposite the side on which the support sleeve 54 and the support mandrel 56 are mounted. The housing 41 is connected to a pack shaft 60 that is rotatably supported by a drive support body 62. The pack shaft 60 is coupled to the gear assembly 44 of the drive assembly 40 such that the drive motor 42 rotates the drive pack 58 in a driving pair. The drive pack 58 has a longitudinal groove in the outer peripheral portion thereof, the longitudinal groove between the outer surface of the drive pack 58 and the inner surface of the roll tube when the drive assembly is received in the roll tube. Assist the engagement. The drive assembly 40 is adapted to be received by the inner portion of the roll tube such that a support sleeve 54 and a support mandrel 56 for the EDU controller 50 are positioned adjacent to the end of the roll tube. The drive assembly 40 also includes a brake 64 having a brake inlet 66, a brake outlet 68, and a brake mandrel 70. The brake 64 defines an inner portion that receives the pack shaft 60, and engages the pack shaft 60 so that the drive motor 42 and the drive pack 58 do not rotate relative to each other. By this engagement, the flexible member portion that has already been unwound and the load of the edge bar material carried by the flexible member are applied to the roll tube, so that the flexible member is prevented from being unwound. Thus, the flexible member is held in the selected position. Brakes for roll tube drive assemblies are known and will not be described further.

Referring to FIG. 6, details of one embodiment of the drive motor 42 and gear assembly 44 of the drive assembly 40 are shown, with the gear assembly 44 including a ring gear 72 received inside a ring gear cover 74. A motor adapter 76 is positioned between the motor 42 and the ring gear cover 74. The motor adapter 76 engages with the ring gear cover 74. The ring gear cover 74 includes a tab 78 that is received in a correspondingly shaped cutout 80 of the motor adapter 76 that restricts relative transfer between the motor adapter 76 and the ring gear cover 74. The ring gear cover 74 also includes an end fitting 82 received by the brake mandrel 70.
The gear assembly 44 includes a sun gear 45 attached to the output shaft 43 of the drive motor 42 so as to rotate with the output shaft 43. The sun gear 45 is preferably pressed onto the output shaft 43. Each of the first and second gear stages 46, 48 of the gear assembly 44 includes three spur gears 96 that mesh with longitudinal gear teeth 96 formed on the inner surface of the ring gear 72. The sun gear 45 meshes with the spur gear of the first gear stage 46, and the spur gear of the first gear stage 46 is rotated by the sun gear 45 at the motor speed. Each spur gear of the first gear stage 46 is rotatably received on each pin 90 of the sun carrier 88, and each spur gear of the second gear stage 48 is rotatably received on each pin 94 of the hexagonal carrier 92. The sun gear 98 is fixed to the sun carrier 88 on the opposite side of the pin 90 and meshes with the spur gears of the second gear stage 48 so that when the sun carrier 88 is driven by the first gear stage 46, the second gear is engaged. Rotate each gear on the stage. The hexagon socket 100 is fixed to the hexagon carrier 92 on the side opposite to the pins 94. The gear assembly 44 also includes a second gear stage adapter 102 that receives the hex head 104 received by the hex socket 100 of the hex carrier 92 and the end of the drive pack shaft 60 on the opposite side of the hex head 104. A socket 106 is included. The second gear stage adapter 102 transmits the rotation of the hexagonal carrier 92 when the hexagonal carrier 92 is driven by the second gear stage 48 to the drive pack 58.

  The EDU controller 50 of the drive assembly 40 preferably controls the speed of the motor 42 at a variable speed. Such variable speed control may be used in a roll tube drive assembly to adjust the speed so that the wrapping motion of the flexible member onto the roll tube ("linear speed" or "fiber speed") is substantially constant. Is desirable. An example of such a control system is disclosed in US patent application Ser. No. 10 / 774,919 filed Feb. 9, 2004, entitled “Control System for Uniform Movement of Multiple Roller Shades”. As the flexible member is wound onto the roll tube, a layer (or “wrap”) of the material of the flexible member is formed. Since this fiber layer changes the radius at which the fiber is received or unwound by the roll tube, if the roll tube is driven at a constant rotational speed, the moving speed of the flexible member is wound around the roll tube. It gets faster as you go. It is known to control the speed of a DC motor using motor voltage control using a pulse width modulation scheme. An example of an electric roll tube system that variably controls the motor speed by a pulse width modulation method is described in US Pat. No. 5,848,634.

  The drive motor 42 of the drive assembly described above is a DC motor, but is preferably a brush type DC motor. In particular, there may be applications where the driven load of the motor is relatively large and it is preferable to use an AC motor rather than a DC motor. Such a situation can occur, for example, when a large number of roll tubes arranged so that the ends are connected are driven by a single motor. In variable speed control using an AC induction motor, not only the voltage to the motor but also the frequency is modulated. An AC induction motor is typically wound with a set of stator windings, each driven with a single AC voltage waveform. Typically, three separate windings are spaced along the peripheral portion of the motor stator and driven with a three-phase AC voltage waveform. Due to the phase displacement of the drive voltage waveform, a rotating magnetic field is generated in the rotating section of the motor, and the magnetic field induced in the rotor and the magnetic field of the stator are repelled to generate a net torque in the rotor. The rotational speed of the rotor is related to the frequency of the drive waveform and the number of electrodes produced by the stator winding structure. This relationship is represented by the formula: n = 120 × F / P. n is the rotor rpm speed, F is the drive voltage frequency in Hertz, and P is the number of electrodes.

The number of electrodes of a commercially available AC induction motor is typically two or four. If it is this form, manufacture of a stator winding will be easy. AC induction motors with 2 and 4 electrodes typically operate at nominal speeds of 3600 rpm and 1800 rpm, respectively, when driven with a 60 Hz drive voltage waveform. Running these types of motors at a speed of about 750 to 900 rpm requires a lower operating frequency, which is possible using a frequency controlled inverter circuit. For example, to drive a 4-pole AC induction motor at a speed of 750 rpm, the drive frequency needs to be about 25 Hz.
As described above, the drive assembly 40 of the present invention is adapted to be received in a rotatably supported roll tube, such as the roll tube 14 shown in FIG. However, the present invention is not limited to use in a cylindrical tube, and the tube that is rotatably supported is rotatably supported and receives a flexible member in a wound state. Any elongate member may be included. Thus, the roll tube can be non-circular in cross section, for example hexagonal or octagonal. The non-circular cross section can also be an asymmetric shape, such as an ellipse.

  Flexible members that wrap around a roll tube system incorporating the drive assembly of the present invention can be shades, screens, curtains, or the like, light blocking or reflecting, or partially blocking or partially reflecting. The flexible member may be formed from paper, cloth, or any type of fiber. Examples of flexible members are window shades, window screens, screens for projectors, including television projectors, total shading or partial shading, or reflective curtains, used to hide or protect items Curtains, included.

  Additional features arise from operating the motor 42 at various speeds using the controller 50. When the motor is operated at a nominal speed of about 1000 rpm, the driving sound is very quiet. When the user interface, such as a wall control station, is activated to issue an action command such as an up or down command, the movement of the flexible member appears to be responsive to the action command input. That is, when the ascending button is pressed, the flexible member moves at an appropriate speed, so that the user can confirm the requested operation. It has been found that operator feedback requirements are met when the flexible member moves at a speed of about 8 cm (3 in) per second. However, the visible feedback condition is greatly reduced when issuing a command to move the flexible member to a specific predetermined position. The operator knows that no additional input to the flexible member is required when issuing a command to move the flexible member into place. That is, after issuing a command, the flexible member moves to a predetermined position even if the user does not hold the command. Therefore, the user can do another work after pressing the button. This mode of operation also has other benefits. Since the preset operation does not require visual feedback of the movement of the flexible member, the motor can move the flexible member at a very slow linear speed (hereinafter “ultra-low speed”).

  The ultra low speed operation mode provides at least two significant benefits. One is that the noise generated from the electric roll tube system is further reduced from below 43 dBA to about 40 dBA. Under most ambient air conditions, a noise level of 40 dBA is not perceptible to humans. Another is that the ultra-low speed of the motor 42 can be selected so that the speed of movement of the flexible member is about 2.54 cm (1 in) per second. This speed corresponds to a motor speed of about 300 rpm. The movement of the flexible member at this speed is hardly noticed by people in the room, and is thus less likely to interfere with indoor activity. This type of electric roll tube system tends to use an automatic control device such as a photocell sensor.

  Conventional lighting systems include systems in which an artificial light source, such as a controlled auxiliary fluorescent lamp positioned next to a window, assists natural light. Control systems that measure the total amount of light in the space and adjust the output of the control-type fluorescent lamp to maintain the amount of ambient light in the room at a predetermined value are generally provided, but the amount of natural light incident on the space is adjusted The electric roll tube system control capability for doing so is limited to open loop control. In open loop control, the flexible shade member of the electric roll tube system is actuated in response to manual control, by timer control, or by ambient light level measurement using sensors. In a conventional attempt to measure the actual room light level and adjust the flexible shade member according to the measured value, the moving speed of the flexible shade member is too fast or too slow, and the amount of light incident on the space is low. Over and under, eventually the control loop system was under-damped and oscillating. If the movement of the flexible shade member is too fast, it will be an obstacle for people in the room. The very slow motion of the present invention and the very slow motion of the associated flexible member allows the slow motion of the flexible member to match the desired response speed at room light levels. It is possible to prevent swinging control that causes discomfort to people in the room.

In accordance with the present invention, an electric roll tube system having at least two separate modes of operation is provided. In the first mode of operation, the system motor is operated at an operating motor speed of about 1000 rpm and the associated flexible member is moved at a linear speed of about 8 cm (3 in). The first mode of operation is beneficial when the operator moves and moves the flexible member to a selected position by using and holding up / down commands that move the flexible member to the desired position. In the present specification, the first operation mode is also referred to as “setup mode”.
In the second mode of operation, the system's motor is operated at an operating motor speed of about 300 rpm, and the associated flexible member moves at a speed of about 2.54 cm (1 in) per second. The second mode of operation is the amount of natural light entering the room when the flexible member is moved to a predetermined position (often referred to as a “preset position”) or during operation in a closed loop control system as described above. This is particularly useful when adjusting
Although the present invention has been described with reference to the embodiments, it should be understood that various modifications can be made within the present invention.
In the appended claims, "flexible member" should be broadly interpreted to include any wrappable member that blocks or reflects light, or partially blocks or partially reflects light. Non-limiting examples of flexible members include shades, screens, curtains.

FIG. 6 is a partially broken perspective view of an electric roll tube system including a conventional drive assembly. FIG. 2 is a perspective view showing a motor and gear assembly of the conventional drive system of FIG. 1. It is a graph of the motor curve of the motor of FIG. 1 is a perspective view of a drive assembly for an electric roll tube system according to the present invention. FIG. FIG. 5 is a perspective view of the gear stage of the motor and gear assembly of FIG. 4 with other drive assembly portions omitted. FIG. 5 is an exploded perspective view of the motor and gear assembly of FIG. 4. It is a graph of the motor curve of the motor of FIG.4 and FIG.5.

Explanation of symbols

40 Roll tube drive assembly 41 Housing 42 Motor 43 Output shaft 44 Gear assembly 46 First gear stage 48 Second gear stage 53 Efficiency curve 55 Shaded area 57 Shaded area

Claims (11)

Electric roll tube system,
A roll tube rotatably supported;
A flexible member engaged with the roll tube and wound around the roll tube;
A motor having an output shaft that rotates at motor speed;
A gear assembly coupled to an output shaft of the motor, the gear assembly including a plurality of gear stages driven by the motor and adapted to generate an output rotational speed reduced with respect to the motor speed;
A controller coupled to the motor for controlling the motor such that the flexible member is wound or unwound with respect to the roll tube;
Including
The control body has at least two operation modes, and each operation mode controls the motor in two operation modes in which the flexible member is moved at a predetermined linear speed, and the linear speed in one operation mode is the other operation. Electric roll tube system different from that in mode. The electric roll tube system according to claim 1, wherein the at least two operation modes include a setup mode and an ultra-low speed mode, and a linear speed in the setup mode is larger than that in the ultra-low speed mode. The electric roll tube system according to claim 2, wherein the linear speed in the setup mode is at least twice that in the ultra-low speed mode. The electric roll tube system of claim 2, wherein the electric roll tube system produces a noise level in any of the at least two modes of operation, and the noise level in the ultra low speed mode is about 3 dBA or less than that in the setup mode. system. The electric roll tube system according to claim 1, wherein the control body adjusts the position of the flexible member in accordance with the level of light incident on the control body. The motorized roll tube system of claim 1, wherein the linear velocity in one of the at least two modes of operation is 2.54 cm per second or less. The electric roll tube system according to claim 2, wherein when the ambient sound pressure level is about 38 dBA, the sound pressure level at a distance of about 1 m from the roll tube is 38 to 40 dBA in the ultra low speed mode of the electric roll tube system. . The electric roll tube system of claim 1, wherein the controller is responsive to a plurality of control signals including a control signal associated with each of the at least two operating modes. The control body can freely respond to the control signal in the setup mode and the preset mode control signal, the control body moves the flexible member at a predetermined linear speed in accordance with each control signal, and the linear speed in the setup mode is preset. The electric roll tube system according to claim 8, wherein the electric roll tube system is at least twice the linear speed in the mode. Electric roll tube system,
A roll tube rotatably supported;
A flexible member engaged with the roll tube and wound around the roll tube;
A motor having an output shaft that rotates at motor speed;
A gear assembly connected to the output shaft of the motor and the roll tube so that when the gear assembly is driven by the motor, the roll tube is driven by the gear assembly to generate a reduced output rotational speed with respect to the motor speed. A gear assembly including a plurality of gear stages,
A controller coupled to the motor adapted to variably control the motor such that the flexible member is wound or unwound at a substantially constant linear speed with respect to the roll tube;
Including
A control body is responsive to a first control signal for controlling the motor to move the flexible member at a first predetermined linear velocity;
An electric roll tube in which the control body is responsive to a second control signal for controlling the motor to move the flexible member at a second predetermined linear speed different from the first predetermined linear speed. system. The electric roll tube system of claim 10, wherein the first predetermined linear velocity is at least twice the second predetermined linear velocity.

Images